This grant request is for a Scanning Laser Acoustic Microscope (Sonoscan Model 100 M with Model 500 M 500 MHz Module). Acoustic microscopy uses high-frequency ultrasound to obtain high resolution images of tissue which complement conventional light- and electron microscopy. The acoustic microscope has the advantage of allowing fresh, unstained tissues of varying thickness to be imaged. Two dimensional images that display the parameters of 1) acoustic attenuation, and 2) acoustic propagation velocity are simultaneously compared with light imaging, an important feature of the scanning laser acoustic microscope. The microscope will be under joint control of the Departments of Ophthalmology, Pathology, and Radiology, and housed in the Department of Ophthalmology along with materials and equipment pertaining to the preparation of materials for microscopy, data analysis and maintenance. The microscope will assume a fundamental role in the support and expansion of on-going N.I.H. supported research in a variety of disciplines and fields of interest - through its ability to quantify acoustic parameters that relate directly to protein constituents and concentrations as well as elastic moduli of the observed tissue.